The present invention relates to high-density, multiple-contact connectors which are used in a variety of applications. For example, in aircraft, such connectors are often used to interface various locations throughout the aircraft with processing circuitry located within an enclosure or black box in the electronics bay bulkhead of the aircraft.
For convenience and flexibility, it is known to manufacture such connectors in the form of modular assemblies in which one or more connector modules or "modules" are supported within an outer shell member. Both the outer shell member and the modules are manufactured in a variety of standard configurations. In order to form a modular connector assembly suitable for a particular application of interest, the appropriate shell member and modules are selected and mounted within the outer shell member. The module containing electrical connector as a whole is then mounted to a bulkhead or other mounting surface for use, providing a mating face along one side of the bulkhead and an opposed electrical connection interface on the other side.
For even greater flexibility, the modules can be removably mounted within the outer shell member.
Replacement of a particular module requires the removal of the module from the outer shell member and the mounting of a new module in its place. Thus, when a module is damaged, it is not necessary to replace the modular connector assembly as a whole or to interfere with other modules in the modular connector assembly, as the damaged module can be removed and replaced without replacing the remaining modules.
In the industry, it is known to design modules that protect circuitry from disruptions caused by electromagnetic interference ("EMI"), including radio frequency interference ("RFI") entering the system In addition to protecting or filtering electronic equipment against EMI/RFI energy, there is also a need to protect the equipment against power surges or suppress transients owing to electrostatic discharges ("ESD") and electromagnetic pulses ("EMP"). The high voltage generated by ESD and EMP can damage voltage sensitive integrated circuits and the like.
Frequently today's electronic circuitry requires the use of high density, multiple contact electrical assemblies. As the newer generation of electronic circuits are increasingly packed into smaller spaces, the circuits become more susceptible to damage from the above types of energy. There are many applications in which it is desirable to provide an assembly with a filter capability; for example, to suppress EMI and RFI, and transient suppression means to suppress EMP and ESD interference or other undesired signals which may exist in circuits connected by the assemblies.
Typical of the prior art describing filter modules are U.S. Pat. Nos. 4,820,174 ("'174 Patent") and 4,699,590 which shows one or more filter modules positioned within an outer conductive shell. Typical of the prior art describing transient suppression modules is U.S. Pat. No. 4,726,638 which shows a transient suppression system for protecting individual circuit boards. Typical of the prior art including both filter and transient suppression protection is U.S. Pat. No. 4,729,743 ("'743 patent") assigned to the assignee of the present invention. The connector assembly described in the '743 patent includes both filter and transient suppression modules mounted within an outer shell member. Grounding paths are provided automatically from the transient and filter modules to the outer shell member by first spring fingers engaged around each filter circuit contact assembly and a plurality of second spring fingers engaged to the conductive outer shell. These modules are especially useful in the high density, multiple contact electrical assemblies of today, which circuits are susceptible to the above types of energy
In prior art connectors, it has been known to utilize the modular connectors described above for this purpose, wherein discrete modules providing protective circuitry are assembled within a sleeve. A problem in the prior art has been effecting proper alignment of the electrical contacts during mounting For example, in high density electrical contact modules, the electrical contacts can be very fragile, and easily damaged if the mating units are not precisely aligned during mounting and subsequent use. Further, slight alignment errors can result in the electrical contacts being arc welded as a result of the high voltages these modules are subject to. In the prior art, ensuring proper alignment has been effected by the use of specialized tools, or prefabricating the modular units into an electrical connector prior to its intended destination.
A particular problem has been the difficulty in replacement of damaged electrical contacts in such a modular unit. During manufacture or use of the connector, one or a few of the contacts may become damaged or broken and require repair or replacement.
In general, many prior art devices require removal and replacement of the module containing the damaged electrical contacts. Because a connector insert may contain as many as 150 separate contacts, replacement of the entire module and all of its associated electrical contacts can be relatively costly. Moreover, if the modular elements are soldered or otherwise permanently attached together or to the sleeve, it is necessary to replace the entire connector and all of the electrical contacts therein in order to overcome the problem of a single damaged contact. For example, U.S. Pat. application Ser. No. 07/818,188, entitled "Modular EMP and EMI Connector Assembly," by Nguyen, filed on Jan. 8, 1992 illustrates full modular replacement, rather than replacement of individual contacts, by using a tool such as disclosed in U. S. patent application Ser. No. 07/818,301 also filed Jan. 8, 1992. Also, due to the availability and cost of the connectors and modular units, it is not always possible to find a replacement module at the site where damage is discovered, causing delays in repair.
Thus, the inability to effect the proper mounting and removal of circuit modules without damaging the electrical contacts therein, and without the use of specialized tools has presented a problem. Further, replacement of damaged electrical contacts in modular and other high density electrical connectors has required the costly replacement of the entire connector or module as a result of damage to one or several relatively inexpensive electrical contacts.
Further still, it has not been possible in many circumstances to repair damaged electrical contacts at the site the damage occurs or is detected. In such cases, repair requires the removal and replacement of the module or connector containing the damaged contact, and the entire unit then being sent to another location to repair the damaged contact. On-site repair has not been possible. This problem has been compounded by frequent unavailability of replacement modules and connectors in non-metropolitan locations, causing further delay in repair.
None of the of the prior art devices described above provide a modular connector assembly having improved assembly characteristics such that they can be installed properly and without damage, using readily available conventional or simple hand tools and without the use of any specialized tools. Nor do any of the above described devices have replacement capabilities such that a damaged electrical connector unit may be replaced by simply and inexpensively replacing the damaged electrical contact, without replacing the entire connector or module unit. Nor do any of the above described devices have the capability of on-site repair through simple replacement of the damaged electrical contact, which contacts are generally widely available.
It is desired to provide separable connector portions having respective shells therearound, securable together at a separable interface and separable thereafter, permitting access to at least the inside face of one of the two connector portions for inserting tools into contact passageways for contact removal from the now exposed inside face and assuring shielding continuity between the shell portions.